Radio telemechanic system



March 20, 1928.

E. ,FIAMMA RADIO TELEMEGHANIC SYSTEM Filed July 1. 1924 \NVENTOR.[K/VAN/VO f/AMMA BY:W

ATTORNEY.

Patented Mar. 20, 1928.

ERMANNO-FIAMMA, OF-AQUILA, ITALY.

RADIO. TELEMEGHANIC. SYSTEM.

Application .filed July 1, 1924-, Serial No." 723,490, and in ItalyJ'une14, 1923.

In the practice of Wireless signalling by electromagnetic Waves thepossibility of obtaining a selective signalling utilizing thecharacteristic of vibrating devices (tuning obtained in practice with atransmitting station equipped with means for producing electromagneticWave trains having a determined frequency for each signal, and areceiving station equipped with number of vvibrating devices equal ,tothe number of signals .to be received, each one of. which vibratingdevices is tunedto enter into full vibration when subjected to periodicimv fthoseof the transmitting apparatus, and any number of these stripsmaybe employed pulses of afrequencylequal to the frequency of the Wavetrains oftlie corresponding sig- For accomplishing said objects in thepresent invention are utilized as vibrating devicesa number of-metallicstrips fixed at one end and free at the other. I

It is well known that, by constructing eachstrip of adetermined length,cross section and weight the fixed period of oscillation with Which thesame strip may vibrate can be easily determined.

These strips,.as described further on, are utilized for transmittingwave trains of a definite frequency and for selectively responding in'the receiving station to a deterniiiiedifrecpiency of Wave trains.

In the drawingsaccompanying and forming partof this specification,

Figs. land 2 are diagrammatic illustrations of a receiving station and atransmit ting station, respectively, embodying the features of thepresent invention. 7

The receiving'station illustrated in Fig. 1 is providedwith a selectingapparatus comprisinga plurality of flexible metallic strips U U U (onlythree being shown in the drawings). One end of each strip is confined inafixedmember, A A A respectively. Each of said strips is formed ofmagnetic metal and is intended to have a periodof oscillation Which isdifferent from that of any other strip of the series. For vibrating thestrips, electromagnets E E which it may be desired to, transmit.

and E one for each strip, vare provided, or the 'fixed members of the"strips may be mechanically connected and a single electrospectively. Ineach of said circuits is ineluded the electric or mechanical device act-.ing when the corresponding signal S S S5 is respectively received.

The, transmitting apparatus illustrated diagrammatically in F g. 2, alsocomprises a plurality. of strips or tongues L ,jL and L mounted inamaunersnnilar to those of the receiving: station The strips of thereceiving station .Wlll: correspond, in number with according to thenumber of different signals y means of-this arrangement a Wide range ofselection 1s obtamed. ,E ach strip of the transmitting apparatus"iscaused to vibrate by means of a corresponding electromagnet, D D and Drespectively, 831d electromagnets being incircuit through individualcontacts C C andC with a battery or other source 'of current 13. Thedimensions and uie ight ofthe successive strips L L and L aresograduated that each strip will vibrate at a determinedfrequency Whichisdifferent from those of the other strips. The transmitting apparatus isprovided with a, second series of strips L 11 and L g whioh' may becalled: transmitters, whilethe' first series, of stripsof thetransmitting apparatus may be termed exciters. Eachistrip 'of the secondseries is graduated to vibrate atthe same frequency as itscorrespondingstrip of the first series, and is d sposed opposite to theelectromagnet-Which operates said corres .ondin stri Whereb theresective L 2; p, y P.

transmitters are tuned to the same frequency as thelr correspondingeXciters. Conse- ..quently, when the strips L L L are "operating, thepulsating flux of the corresponding electromagnets will cause the v1-bratlon of the strips 1/ L,, L,, Which in turn will alternately open andclose-a circuit at C,, C and C' respectively, said and soon.

circuits also including manually operable switchesT T T respectively,connected in parallel to the terminals S and S of the antenna-earthcircuit of the transmitting station.

It is to be understood that the transmitting device is capable ofradiating a series of trains of electromagnetic waves separated by equalintervals, the number of wave trains emitted in a second being subjectto change at the will of the operator. Assuming that the number of wavetrains emitted in a second by the respective devices at the transmittingstation are 12 ,11 and M, respectively, the operation of the switch Twill cause the antenna-earth circuit, represented in the drawings by theterminals S S to be closed n, times in a second by the strip L,, andthere will be an emission of small n, wave trains in a unit of time. Byclosing the switch T there will be a corresponding emission of small a,wave trains per second,

graduating the different strips so that the frequency of vibration ofeach couple (comprising exciter andtransmitter) of the transmittingdevice is equal to the frequency of vibration of the correspondingstrips of the receiving device, the latter stripswill be vibrated'inresponse to the operation of the respective switches T, T and T of thetransmitting device, and consequently a connection will be establishedbetween the tertit) minals S S S to operate any device connectedtherewith.

From the foregoing, it will be obvious that the flux generated by eachelectromagnet will pulsate at itsindividual frequency, and consequentlyonly that particular strip of the receiving station which is tuned tothat of a particular strip of the transmitting device, will oscillate,and therefore only the apparatus operated by that particular strip ofthe receiving station will function during that period of time. F orinstance, should the wave trains during a second radiating from thetransmitting station be M, the current flowing through theelectromagnets of the receiving station will pulsate at the frequency M,the magnetic flux will do the same, and the strip U of the correspondingperiod only will. vibrate, thus causing the apparatus associated withthe terminal member S to function. I

It will be evident that inorder to ensure the functioning of thedifferent selectors, it must be possible to radiate from thetransmitting station a series of wave trains the duration of which canbe regulated at the will of the operator, and that the number It willthus be seen that by The set of vibratory strips of the transmittingdevice may be inserted by means of the terminals S 8* in place of thekey or the microphone of a continuous wave radio transmitting station ofany type, or in the primary circuit of a spark station, either alone orcoupled to relays or electromagnetic amplifiers, for the purpose ofinterrupting or modulating the emissions of continuous waves orproducing the emissions of wave trains having a given frequency, whichmay be chosen at will within the limits ofthe receiving strips.

Having thus described my invention, what I claim is: p

In a radiotelemechanical system a transmitting station equipped with anumber of modulators equal to the number of orders to be transmitted,consisting each of a group of two bands of reeds ofmagnetic-metal,secured at one end and free at the other, tuned byconstruction to a determined frequency of vibration equal for the twobands of the same modulator, but different for each modulator, and keptvibrating by an electromagnet whose circuit is periodically interruptedby a contact made by one of the bands in its vibration, while the otherband makes a similar contact which can-be inserted at will oftheoperator in the circuits of the transmitting station, so as to causethe'emission of a wave train for eachfvibration of the band, and areceiving station equipped with a selector consisting inan'electr-omagnet whose armature is connected to a number of metallicreeds equal to the number of signals to be received secured at one endand free at the other, and tuned each to a frequencyof vibration equalto the frequency of the corresponding transmitting modulator. theeleetromagnet being connected to the radio receiver conveniently tuned,and each of the receiving reeds, when in vibration closing a contactcausing the electromechanical execution of the corresponding order.

In testimony whereof I have hereunto signed my name.

ERMANNO FIAMMA.

